ENGINEERED THROUGH CHOICE™
CHOOSE BETTER.
Every ingredient. Every material. Every decision. At OPTIN, we believe better outcomes begin with better choices. That's why every product is intentionally designed to help you perform, recover, and live well.
Treat Their Health
Love Their Heart
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ONE DAILY FORMULA. COMPLETE DAILY SUPPORT.
Why Pet Owners Switch To K91
Joint & Mobility
Supports hips and joints for active dogs
Immune Health
Daily vitamins to help maintain immunity
Heart Health
Essential nutrients for long-term wellness
Skin & Coat
Healthy skin and a soft, shiny coat
Digestive Support
Supports nutrient absorption
Daily Energy
Complete nutritional support daily
OPTIN FLOW ™
BETTER CIRCULATION.
BETTER PERFORMANCE.
BETTER YOU.
A premium tincture formulated with powerful botanicals and nutrients to support healthy cirulation, endurance, and daily recovery.
SUPPORTS
CIRCULATION
SUPPORTS
ENDURANCE
SUPPORTS
RECOVERY
EVERY PRODUCT
STARTS WITH A CHOICE
Before FLOW ever reaches your hands, thousands of decisions have already been made.
- Performance-first formulation
- Premium ingredient sourcing
- Quality-controlled manufacturing
- Tested for consistency
- Built for everyday use
Great products aren't discovered. They're engineered.
WHY WE BUILD THIS WAYINGREDIENTS
Choosen for purpose,
not popularity.
MATERIALS
Selected for
performance.
STANDARDS
Set high. Never
compromised.
THE OPTIN DIFFERENCE
Every product begins with one question:
"Does this actually improve performance?"
PREMIUM FORMULATION
Only ingredients that serve a purpose make the formula.
BUILT TO LAST
Whether it's apparel or nutrition, durability matters.
NO SHORTCUTS
Quality isn't an upgrade.
It's the starting point.
OUR VISION
BUILDING THE FUTURE OF PERFORMANCE.
FLOW is only the beginning.
OPTIN is creating a growing ecosystem of products engineered to help people fuel, move, recover and perform.
From daily nutrition to technical apparel and future innovations, every product shares the same philosophy:
Choose Better. Build Better. Perform Better.
FUEL BETTER
MOVE BETTER
LIVE BETTER
APPAREL
ENGINEERED FOR EVERYDAY PERFORMANCE.
Performance isn't limited to what you consume.
Our apparel is built with the same attection to comfort, fit, durability and function that guides every OPTIN product.
SHOP APPAREL
THE OPTIN STANDARD
If a product doesn't meet our standard...
It doesn't carry our name.
Premium
Ingredients
Science
Backed
cGMP
Certified
Third Party
Tested
Made In
USA
Helping Pets Feel Their Best, Naturally. Shop by category
Hip & Joint
Supports mobility and reduces inflammation
Calming
Eases anxiety and promotes relaxation
Skin & Coat
Improves coat shine and reduces shedding
Digestion
Helps support normal gut flora and bowel movement
Pet Parent Favorites
Daily wellness made simple.
A simple tincture that helps support digestion, joint health, skin, immunity, and everyday wellness
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Real Dog Owners. Real Daily Routines.
Developed for Daily Wellness. Guided by Nutrition Science.
Every K91 formula is thoughtfully crafted with veterinary nutrition principles to support digestion, mobility, immunity, and overall wellness.
- Every ingredient has a purpose
- Developed using veterinary nutrition principles
PAWS OR CANCEL ANYTIME
Save with K91 Club
DONATION
Every Bottle Gives Back
Pet Wellness Made Easy
Easy Liquid Formula
Mix with food or serve directly
Clean Ingredients
No artificial fillers, colors, or flavors
Vet Recommended
Formulated and endorsed by veterinarians
Made in the USA
Produced in FDA-certified facility
Why Pet Parents Choose K91
Sam
I can't say enough good things about K91 supplements! My dog Max had been struggling with digestive issues for months. Within just a few weeks, the change in Max was incredible! His energy levels bounced back, his digestion improved.
Emily
I was amazed by the results of K91s Skin and Coat Supplement! A friend recommended K91 Skin and Coat Supplement, so I decided to give it a try. After just a few weeks, the difference was incredible!
Stan
A friend recommended K91 skin and coat supplement. I was skeptical at first, but after a few weeks of adding it to Max’s diet, the results were amazing! His coat became shiny and soft, and the itching stopped completely.
Olivia
My dog Rocky has always been anxious, especially during thunderstorms and when left alone. I discovered K91 calming supplement. Within days of starting him on it, I noticed a huge difference.
Jessica
K91 probiotic supplement has helped tremensly! Within just a couple of weeks, I noticed a significant improvement. Rocco digestion has stabilized, his energy levels are back.
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OUR MISSION
To engineer products that help people perform at their best through intentional choices.
Built with intention. Proven through performance.
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Join our community for product launches, engineering insights, and performance education.
Engineered Through Choice™ Products engineered to help people fuel, move, recover, and live better.
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